Pressure-applying machine.



D. A. MURPHY. PRESSURE APPLYING MACHINE. APPLICATION FILED-FEB. 13, 1908.

Patented Dec; 29, 1908.

DAVID ALLEN MURPHY, or wEs'rMoUNr, QUEBEC, CANADA.

PRE'ssURE-APrLYING MACHINE.

Specification of Letters Patent.

Patented Dec.29, 1908.

Application filed February 13, 1908. i Serial N o. 415,777.

To all whom it may concern:

Be it known that I, DAVID ALLEN MUR- PHY, of VVestmount, Province of Quebec, Canada, have invented certain new and useful Improvements in Pressure-Applying Machines; and I do hereby declare that the following is 'a full, clear, and exact description of the same.

`My invention has for its object to provide a pressure applying machine to maintain a uniform high pressure during a certain ldefinite ortion of the action of the operative member thereof, and to this end the invention may be said briefly to consist of the combination with the operative member of such machine, of intermediary means between the initial power exerting member and the operative member whereby a force is transmitted increasing to a maximum attained before the completion of 'the operative movement and maintaining such maximum throughout the balance of -the said movement.

For the purposes of illustration I have shown my invention applied to a riveter in which the operative member is the ram and the initial power exerting member the cylinder and piston.

The well known type of riveter .in connec tion with which I have illustrated my' invention utilizes iston driven oscillatory tension links pivotedp at their lower ends to the frame of the machineand a compression .link oscillated by the same piston and pivotally connected to the ram, the action being that the reciprocation of the 'piston conin'ed by theA tension links within a certian fixed radius causes the compression link to exert a toggle action upon the ram and alternately force it downwards in its power stroke, and return it to its normal position. In this instance the invention is applied to the tension. links which are constructed to contract slightly when the piston is finishing its operating stroke for the purpose of causing the ram to operate with a force increasing until it attains a maximum which it does before the completion of its stroke, andfmaintai'n this maximum force through the balance of the stroke.

The invention'further consists tf a simpaed piston operating gear. i

For :full comprehension, however, 'of my invention reference-'must be had to the 'ae' companying drawings forming a part ofthis specification, wherein corresponding 'reference numerals indicate the same parts, and in which- Figure 1 is a side'elevation of a riveter pro vided with my invention, the cylinder being partly broken away; Fig. 2 is a front elevation with one half in transverse vertical sectional view; Figs. 3 and 4 are detail views illustrating the links in different working ositions; and Fig. 5 is a diagram illustrating the leverage action ofmy invention.

The cylinder b, piston c, piston rod d, compression link e, ram f and frame g including the ram .guide 7c are of usual construction and therefore will not be described in detail. The usual stops m are provided at the op osite sides of the ram guide to limit the orward stroke of the tension links. tension linksare, according to my invention, each formed of a lower member pivoted at its lower` end as 'at 3 'to' the vram guide, and a pair of upper members 4 located at opposite sides of and pivoted at their lower ends, as at 5, 'to the 'upper end of 'the lower member, while the upper ends o f suoli members 4 are ivotally mounted upon a pin which also ias the end of the piston rod d, and the upper end of the toggle or compression link c pivoted thereon. The lower members 2 of the ltension links are formed with projections 7.

of T `fo'rmvexte'nding from the said lower` member. y

When the "istonis in its 'full back position the lower an upper members of each tension link are in alinement. As the piston moves in its power stroke these members maintain such alinement until the lower members come into contact with the stops m thereby causing these links to contract as the piston continues to the end of its stroke and turns the upper member on the lower member thus shortening the4 distance between the pivot points 3 and 6 and, forcing with practically uniform leverage, the com resslon toggle link and the ram downward y to a proportionall'y greater extent.

.In order to 'maintain 'the/.lower members 2 of the tension .links yielding? in their prpiper working positions, a pair o small cy in' ers l5 are fixed to and located one at each side These l of the machine frame, and each contains a. spring 16 and a piston 17, while such pistons are connected at 18 to the said lower members. These yielding devices have no function to perform unless the machine is operated without rivets being fed thereto.

In order to economize motive Huid in the return stroke of tlie piston and at the same time enable the machine to be operated by a valve ltlcontrolling the supply of the fluid to one side only of the piston, a pair ol com- -paratively small bore cylinders 2() project from the cylinder head 21 and communicate with the interior of the main cylinder and pistons 22 within such cylinders 2O are connected to the main piston by piston rods 23. A branch pipe 24 leading from the main motive fluid supply pipe (not shown) is connected tothe outer ends of these small bore cylinders and a power is thus maintained just sufficient to return the piston and which c will not appreeiably interfere with the movement of the piston in its power stroke.

In the'present embodiment of my invention the parts of the machine are assembled and adjusted to cause the piston rod in completing` its possible stroke to carry the upper end of the toggle or compression link e a short distance beyond the axial line of the ram7 but if desired such arrangement can be varied to cause the limit of its stroke to be in the axial line of the ram or at any angular position relatively thereto within reasonable limits without changing the force of the ram.

Operation: During the power stroke, the members of each tension link move in unison (as if in one piece) with the piston rod and up to the moment the lower members 2 are stalled by the stops m the action of the machine is exactly as heretoforek in this type of riveter, in that the compression link forces the ram downwardly. In the ma chines as formerly constructed, however, the contact of the tension links with the stops was the limit of the power stroke of the ram. With this invention, however, the lower members being stopped the upper members 4 turn thereon, the tension links thus contract and shorten the distance between their extremities and consequently as their lower ends are fixed against other movement than rotary the eilect is that the ram is driven downwards beyond the position it momentarily assumes when the lower members were stopped, and during the remainder of the stroke while the piston rod continues until the ram is stalled by the work or the piston rod ,reaches the limit of its possible stroke, the ram is forced downwardly with practically uniform leverage due to the fact that the upper member 4 of each contractible link rotates around the center 5 and that the compression link e travels'with it without such members appreciably changing their relative angular position (see Fig. 5), with .the result that a practically uniform come pressive force is exerted from the time the tension links commence to contract until the ram is stalled. rl`his action is due to the followingA conditions: rIhe maximum force attained when the points 3, 5, 6 are in line, or in other words at the instant the link 2 is stalled by the stop m. In diagram, Fig. 3, the full lines illustrate the parts in the pesi tion they momentarily assume at the instant such maximum force is attained, and the dotted lines indicate the parts in thc pesitions they assume at the end of the stroke. rl`he imaginary line Y extending at right angles from the center line of the ram to the center 5 .iixed by the stalling ot' link 2 as throughout the balance of the stroke, while the imaginary line V extending at right angles from the line l (dcnoting'thc line of force of the piston rod) to the said center 5, also remains of practically uniform length. Therefore because the force I) constant and the distances represented by the lines V and Y remain practically coinistant, thc force exerted. by the ram during` the balance of the stroke is also practically constant, and consequently the maximum force attained when the points 3, 5 and G are in line is maintained throughout the balance ol' the stroke.

What I claim is as fellows:

1. The combination with a ram, a pow'er driven member mozable across the direction of moi'ement of the ram, a '-onlractible member operativ 4ely connecting the power dri en member to the ram, and mea-ns for causing the said member to contract and during contraction exert its maximum force.

2. In a ri eter, the combination with the frame of the machine, a ram, a piston rod and a toggle link operati' 'ely connecting the piston rod to the ram, ol a ljointed link connecting the piston rod tothe frame of the. machine, and meansl for causing the said link to bend before the completion of the power stroke of the piston.

3. In a ri'.eter, the combination with thc frame of the machine, a ram, a piston rod and a toggle link opera-ti' ely connecting the piston rod to the ram, of a jointed link connecting the piston rod to the frame of the machine, and a stop upon the frame for causing the said link to bend before the completion of the power stroke of the piston.

4. In a ri jeter, the combination with the frame of the machine, a rain, a piston rod and a toggle link operati Aely connecting the piston rod to the ram, of a jointed link connecting the piston rod to the frame of the machine, and constructed to bend in one direction only and means for causing the vsaid link to bend before the completion of the power stroke of the piston.

5. In a rix'eter, the combination with the just described, remains of constant lengthframe presenting a ram guilde, a'ram slidable nected at their upper ends to the piston rodcoaxially with the piotal connection of the. vtoggle link, and at their lower ends to opposite sides of the ram guide, and means Whereby the said pair of links are caused to contract befre the completion of the stroke of the piston.

6. In a rit-eter,- the combination with the frame presenting a ram guide with laterally extending stops at its opposite sides, a ram slidable in the guide, a piston rod .reciproeating trans ,'ersely to the direction of motion of the ram, anda to gle link pi'rotally connected at one end to t e piston rod and its opposite end to the ram, of a pair of links adapted to .bend in one direction and connected at their upper ends to the piston rod coaxially with the pivotal connectlon of the toggle link, and 'at their lower ends to oppo site sides of theA ram guide, each link of the 'said pair consisting of upper and lower members carrying de ices pre'.'enting bending in the opposite direction, the lower members being adapted .to engave the said stops whereby the said pair of'links are caused to contract before the completion of the stroke of the piston. l

f7. ln a riveter, the combination with the frame of the machine, a ram, a piston rod z and a toggle link operatively connecting the piston rod to the ram, of a jointed link connecting the piston rod to the frameof the machine, and constructed to bend in one direction only `means yieldin ly retaining the members of'each jointed lin m Working position, and means for causing the said link to bend before the completion of the power stroke of the piston.

8. Ina 1'i'.'eter, the combination with the frame of the machine, a ram, a piston rod and a toggle link operati-.ely connecting the piston rod to the ram, of a jointed link connecting the piston rod tothe frame of the machine, and constructed to bend in one direction only, a pair of cylinders each containing a spring anda piston, and a pair 'of rods projecting from the pistons, the cylinders being secured to the machine frame at opposite sides thereof and the rods to the lower members yieldin" ly retaining the members of each jointed. mk in working po- .'sition, and means for vcausing the said link two subscribing witnesses.

.DAVID ALLEN MURPHY.

Witnesses:

WILLIAM P. MCFE'AT, ARTHUR H. EVANS. 

